Nickel-catalyzed sebacic acid production in the presence of barium compounds



United States Patent Ofiice .NICKEL-CATALYZED SEBAQIC ACID 'IPRQDUC- 'TIQN INTHE PRZESE CE UF BA RIUM "COM- POUNDS Frank C. Naughton, NorthvBergen, N. J., assignor to The .Baker (Iastor Oil Company, Jersey City, NHL, a corporation of New Jersey No Drawing. Application ctober-29, 1954 Serial No. 465,723

14Claims. 7 (Cl. Mil-+537) This invention relates to the nickel-catalyzed converxsioncf ricinoleic compoundsinto other organic com- .pounds,.including sebacic acid and salts thereof, bymeans of .an alkali fusionv process. Thisprocessis characterized by .the presence of. bariumcompounds in the alkalinebath in which the conversion is effected.

, It has been known in the past to, prepare ,sebacicacid .and, related compounds by thealkali fusion ofricinoleic .derivati-ves. However, serious difliculties havebeenv encountered; namely, violent foaming, incomplete reaction ,due to thetransformation of the reaction mixture into a vrigidimass during the heating, and the required neutralization ofjthe alkali bath in the. process of recovering sebacic acid vtherefrom. Attempts to overcome the prior .art

.difiiculties, have involved the use of-super-atmospheric pressures. and aconsequent need for cumbersome equipment, slow addition of the ricinoleate to the reaction bath, or the presence of highboiling, inert organic liquids.

Theuneed for these unsatisfactory. expedients has. been overcome in the process described below.

.ltis an object of this invention toprepare sebacic acid and related compoundsbyan improved alkaline fusion process. Another objectis toprovide a. process which enablesrecovery of sebacic acid Without neutralization of the alkaline bath. It isa furtherobject to eliminate thefoaming and incomplete reactiondifliculties encoun- :tered.,in the past. It is also an object of this; invention .to eliminate the need for conductingthe reaction under super-atmospheric pressures, in the presence ofinert organic liquids, and thelike. A further objectis to provide .a simple, continuous process for the conversion of the. invention.

Ithas noW been found thatthe conversion of'ricinoleic .compouhds bymeans of alkali fusionproceedssmoothly andrapidly when a barium compound isadded to :the

alkali bath in which the conversion is effected, and that .the yields of desired products can be greatly :increased ,When the conversion is conducted in the presence :of: a .catalyst consisting .of nickel or a nickel compound. In

general, the process ofthis invention involves usingla sheated bath comprising an alkali metal: hydroxide and a barium compound, .adding; a ricinoleic compound,iwater, .anda catalyst thereto, collecting and condensingtheicrude capryl alcohol vapors, removing the solidbarium sebacate fromthe fusion bath .by filtrationuwithout neutralization,

. recovering sebacic acid-:anda barium compoundfrom'the barium sebacate; and recycling .the. barium compound: to the fusion bath.

The fu'sion bath contains-an alkali metal hydroxide,

'such as sodium hydroxide, potassium hydroxide, or

2,851,493 Patented Sept. 9, 1958 .lithium hydroxide. .Sodium hydroxide is the preferred alkali metal hydroxide fromthe solubility standpoint, the maintaining of fluidity in the fusion -bath being best .achieved twiththis hydroxide. The barium compound tincor-porated in,the. fusion bath may be a water-soluble, ionizable barium compound or a barium compound which 'is converted into a-water-soluble, ionizable compound under the reactionconditions, typical suitablebarium compounds being barium hydroxide, barium oxide, barium chloride, barium bromide, barium iodide; barium .hypophosphite, barium ricinoleate, barium formate; bar- 'iurn' acetate, barium propionate, barium: phenolate,= and the like. From about'2.0 to about 5.0.moles -ofthe barium compound and from about '10 to about-20 moles ofthealkali metal hydroxide shouldpreferablybe presentvin"the-fusion.bath permole of effective. ricinoleic compound charged. thereto. Satisfactory results are at- .atained:if.:the fusion. bathcontains at least about-0.5 mole of the .bariumxcom-pound and. at least about-5..O..molesiof .thealkali.metal'hydroxide permole of effective ricinoleic compound. .Etfec'tive ricinoleic compound refers to each. available. ricinoleicchain; for example, in the case Lo'f;.castor oil,-.there..are three-.such chains per molecule.

i'fhecatalysts of this-invention are nickel and nickel compounds-selected from the groupconsisting of inor- :ganictnickel compounds and nickel salts of organic acids. ,Typicaliniekel compounds-Within this category include, .byzway ofsexample, nickel monoxide, nickel sesqui-oxide, nickel. tetroxide, nickel chloride, nickel carbonate,'nickelous hydroxide; nickel orthophosphate, nickel py-rophosphate, nickel hypophosphite, nickel sulfate, nickel acetate, '.nicke1'.'benzoate, nickel oxalate, nickel citrate, ni'ckel'tartrate, nickel ricinoleate, nickel heptanoate, 'ni'ckel unde- -cenoate,-nickel laurate, nickel oleate, and nickel' l2- hydroxystearate. When metallic nickel is used as the .catalyst,- it-"should preferably be in finely divided form. The advantages of this invention are attained when the catalyst ispresent in an amount of from about 0.2 to about 20 wt. percent (calculated on the basis of Ni), based on the amount'of ricinoleic compound-being-subjected to alkali fusion.

The ricinoleic compound used in the process of this invention is preferably an alkali ricinoleate. However, other ricinoleic compoundsare suitable for use in the process ofthis invention, and include castor oil, other ricinoleic acid esters, such as methyl ricinoleate, capryl ricinoleate, and propylene glycol ricinoleate, ricinoleic acid, ricinoleic acid amides, ricinoleyl alcohol, ricinoleyl alcohol esters, and the like. The preferred alkali ricin- 'oleates maybe the salts of alkali or alkaline earth metals, e; g., sodium, potassium, lithium, calcium, and barium.

"In addition to the other constituents, there should be presentin the reaction zone from about 4 to about Smoles of water 'per mole of efiective ricinoleic compound. This result'can be achieved by appropriate additions of Water to thereaction zone during the course of. the reaction, by: in situ formation of .Water during the sapo'nification of the ricinoleic compound, or by introduction of the water inthe form of steam or superheated steam. A satisfactoryeamountof water in the fusion.bath,,prior to..its beingheated, is up to about 20%of Water by-weight;

iTheg .processiof this invention is conducted at tempera- ..tures -ran'ging fromabout 225 toabout 375 C. .The ipre Freda-temperature conditions involve 'maintainingthe fusion bath at-a temperature of from about 225 to about 1-300 C. alihereaction is normally effected underipartial reflux conditions. The reaction enclosure maybe constructed" of any suitable material, nickel and nickel alloys beingexemplary thereof. The indicated reaction temperatures can suitably be'attained through the application of external heat to the reactor, or by the introduction of steam or superheated steam into the reactor.

The use of an alkali metal hydroxide, such as sodium hydroxide, in the fusion bath is desirable from an economic standpoint. However, this hydroxide could not be entirely replaced, in any case, by barium hydroxide, since barium hydroxide loses its water of crystallization at about 110 C., and the resulting anhydrous compound does not melt within the range of reaction temperatures for this reaction. This is unsatisfactory, since fluidity of the fusion bath is an important factor in maintaining a smooth, rapid reaction. In this connection, it should be pointed out that calcium hydroxide i an unsatisfactory constituent of the fusion bath, since baths containing calcium hydroxide, even when an alkali metal hydroxide is present, remain solid within the range of reaction temperatures for the process of this invention.

It has been determined that the reaction is complete as soonas the addition of the ricinoleic compound to the reaction zone has been finished. This is one reason why the reaction can be conducted effectively on a continuous basis. The rate of addition of ricinoleic compound to the reaction zone is not critical. In the examples presented herewith, a convenient rate of addition was from about 0.5 to about 1.0 mole of ricinoleic compound per hour.

As indicated, the fusion bath is maintained in a fluid condition, and this eliminates the difficulty encountered in the prior art with the formation of lumps and consequent incomplete reactions. Another principal prior art difliculty, namely, bad foaming, is noted throughout the entire reaction temperature range if the barium compound is absent from the fusion bath. But, surprisingly, foaming is eliminated by the incorporation of the barium compound in the bath. Also, as indicated, the yields of desired products are considerably benefited by the use of the catalysts of this invention.

The volatile reaction products and water vapor are taken ofi overhead through a partial reflux system. The principal volatile product, capryl alcohol, is recovered, along with any other condensable products such as methyl hexyl ketone, by passing the volatiles through a condenser system.

The barium sebacate formed in the reaction is insoluble in the fusion bath, and thus is readily separable therefrom. This produces a decided advantage in the recovery of the sebacic acid, since neutralization of the alkali bath is eliminated. As noted, prior art methods have required such neutralization, and this meant the effective loss of the alkali bath in the recovery of the sebacic acid therefrom.

In the .case of batch reactions, subsequent to the completion of the reaction, the fusion bath can suitably be cooled and diluted with water to a solute content of substantially less than 50%, the barium sebacate being separated therefrom by filtration. The sebacic acid is obtained by acidification of the barium sebacate with a mineral acid, the sebacic acid formed being insoluble and recoverable by filtration. The sebacic acid may be purified thereafter by solution in hot water and subsequent precipitation by cooling of the solution. When the acidification step is effected with hydrochloric acid, the filtrate resulting from the separation of the sebacic acid contains barium chloride. This filtrate can be combined with the filtrate containing barium hydroxide and alkali metal hydroxide from the barium sebacate filtration, and the resulting solution concentrated to at least a 50% concentration. In this step, alkali metal chloride precipitates, and is separated by filtration. The resulting filtrate contains barium hydroxide and alkali metal hydroxide, and can be returned to the reaction enclosure for reaction with further quantities of the ricinoleic compound in the presence of a catalyst of this invention.

This procedure enables the re-use of the barium compound or compounds in the fusion bath substantially without loss. This feature represents an important advantage of the process, since it means that the additive which effects the processing improvements of this invention can be used without causing the increased operating cost which would result if the barium compounds were consumed in each run.

If desired, and especially in connection with a continuous reaction process, the fusion bath can be filtered, hot or cold, at a solute content of about 50%. This could involve little or no dilution of the fusion bath. The barium sebacate could then be worked up as per the foregoing description. On acidification of the barium sebacate, some alkali metal chloride may precipitate with the sebacic acid, but the metal chloride can be readily removed by water-washing.

Examples of the process of this invention and the advantages thereof are given below, in comparison with a run in which the nickel catalyst is absent: 1

Example 1. (N0 catalyst) The reaction was conducted in an Inconel pot, about 6 inches in diameter and about 9 inches high. The pot was equipped with a tight-fitting glass dome, which had three openings fitted with the following equipment: a metallic thermometer for recording the temperature of the reaction mass, the thermometer being replaced, when the desired reaction temperature was attained, by a powder funnel having an opening of about /2 inch in diameter; a motor-driven agitator with a sweeping-type paddle, the agitator shaft being passed through a stainless steel stuffing box; and a Y-adapter, one neck of which was fitted with a charging separatory funnel, and the other neck being fitted with a partial condenser to permit refluxing of some of the distillate (a downward condenser was attached at the upper end of the partial condenser).

The Inconel pot and contents were heated by means of a heat transfer salt bath, a suitable composition for same being as follows: potassium nitrate 53%, sodium nitrate 7%, and sodium nitrite 40%.

The Inconel pot was charged with 36 moles of sodium hydroxide (1440 g.) and 1 mole of barium chloride (208 g.). This charge was thoroughly mixed, and the reactor dome with the indicated attachments was fitted into place. Heating was started, and, when the temperature of the pot contents reached 250 C., the powder funnel was inserted into the indicated dome opening. One mole of barium ricinoleate (732 g.) was charged to the reactor over a period of 1.5 hours, suflicient barium ricinoleate being present in the funnel to maintain a seal thereon. During the period of barium ricinoleate addition, water was also charged to the reactor in a slow drop-wise manner through the charging separatory funnel. Also, during this same period, the salt bath was held at a temperature of 275"280 C., in order to maintain a reaction temperature of approximately 250 C. The water addition was continued after completion of the barium ricinoleate addition in order to recover further capryl alcohol by steam distillation of the reaction mass. Heating of the salt bath was continued for about 5 minutes after the completion of the barium ricinoleate addition and the water addition was continued until the temperature of the reaction mass-had dropped to l70-l80 C., this cooling step requiring from 0.5 to 0.75 hour. The Inconel pot was then removed from the salt bath. The total recovery of capryl alcohol in the distillate amounted to 130.5 g., or 55.8% of the theoretical yield.

As regards the recovery of sebacic acid from the fusion product, the latter was added slowly to about 3 liters of water in a stainless steel pail. The insoluble barium sebacate was then separated by filtration, a sintered steel funnel being used for this purpose. Barium hydroxide was added to the filtrate, and any resulting precipitate of barium sebacate was separated and combined with the previously separated barium sebacate. The amount of wet barium sebacate (tech.) recovered was 1587 g.

Sebacic acid was recovered from the barium sebacate by placing 250 g. of the latter material in a 4 liter glass :initial reactor charge.

beaker, acidifying same with dilute hydrochloric acid, and bringing the beaker contents to a boil. The upper fatty layer (containing reaction by-products), which had formed during the heating, was decanted While hot.

This layer was washed 5 times with betweenl and, 2

.liters of boiling water per wash. The washings were combined with the original aqueous layer, and the whole was cooled; the thus precipitated sebacic acid was. separated byfiltration, and was dried in, an ovenforv 2 hours at 110 C. The recovery of sebacic acid amounted to 30.5 g., which would be equivalent to a total yield of 193.5 g., or 54.0% of the theoretic'alyield.

'ExampZeZ. (2.4.wt. percent ofnickel) The charge in this example was the same as in. Example 1 1, except for the inclusion of 20 g. of Rufert nickel catalyst (25% of nickel in hardened cottonseed oil) in the initial reactor charge and'50 g. of Rufert nickel catalyst in the barium ricinoleate charge, being thoro ghly mixed therewith (2.4 wt. percent of nickel, based onthe amount of barium ricinoleate charged). The .procedural .steps described in Example lwere followed inthis example. ,The capryl alcohol recovered amounted to'1 51 g.,- corresponding to a yield of 4.5% of theoretical (representing a 15.6% increase over the yield of capryl alcohol in. Example 1). The sebacic acid recovery amounted to 260 g., corresponding to a yield of 72.3% of theoretical (representing a 33.9% increase over the ,sebacicacid yield in Example 1).

Example 3. (0.34. wt. percent ofim'ckel) The chargeand procedure in'lthis example werei. the same as in Example 1, except forthe inclusion .of 10 g.

, of Rufert nickel catalyst (0.34 Wt. percent of nickel, based on the amount of barium ricinoleate charged) in the The capr'yl alcohol recovered amounted to 162 g., corresponding. to a yield of'69'.2 of theoretical (representing a 24.0% increase over the yield or" caprylalcohol in Example 1). {The-sebacic acid recovery amounted to 240 g., corresponding to. a..yield of 67.0% of theoretical (representingal24.1% increase over the sebacic acid yield in Example 1).

Example 4. (10 wt. percentofinickel) in the corresponding run made without catalyst.

Example 5. (20 wt. percent of nickel monoxide) .As in Example 4, two comparative-runs weremadeto ..determine the etfect of the use of the indicated catal-yst. I'The chargeand procedure in this example were the same as in Example 1, except for the inclusion of 186g. ofnickel monoxide (20 wt. percent, calculated on the basis of Ni,

1 and based on the amount ofbarium ricinoleate charged) in the initial reactor charge in the catalyzed run. "The sebacic acid yield in the catalyzed run represented an increase of 34.2% over the sebacic acid yield in the corresponding run made without catalyst.

Example 6. wt. percent of nickel sesquioxiae) As in Example 4, two comparative runs were made to determine the effect of the use of the indicated catalyst. The charge and procedure in this example were the same as in Example 1, except for the inclusion of 155.5 g. of nickel sesquioxide (15 wt. percent, calculated on the basis of Ni, and based on the amount of barium ricinoleate charged) in the initial reactor charge in the catalyzed 6 run. The sebacic. acid yield in the catalyzed run rep resented an increaseof33.4'% over the sebacic acid yield in the corresponding run made without catalyst.

Example 7. (7.5 wt. percentof nickel 'tetroxia'e) As in Example 4, two. comparative runs were made to determine the effect of the use or" the indicated catalyst. The charge and procedure in this example-were the same as in Example 1, except for the inclusion of 75.2 g. of

nickel :tetroxide (7.5 Wt. percent, calculated on the basis of Ni, and based on the amount. of barium ricinoleate charged) in the initial reactor .chargein the catalyzed run. The sebacic acid yield in the catalyzed run represented'an increase of 30.9% over the sebacic acid yield in. the corresponding runmade without catalyst.

Example 8. (3.5 wz; percent of nickel carbonate) yield in the corresponding run made without catalyst.

Example 9. (6.0 wt. percent of nickel acetate) As in Example 4, two comparative runs were made ,todetermine'the effect of the use of theindicated catalyst. The charge .and procedure in this example were the. same as inv Example 1,. except for the inclusionof :132.7 g. of nickel acetate (6.0 wt. percent, calculated on .the basis of Ni, and basedon the amount of barium ricinoleate charged) in the. initial reactor charge .in the catalyzed run. The sebacic; acid'yield in the catalyzed run represented an increase of 30.3%;over the sebacic acid yield in the corresponding run made without catalyst.

Example 10. (7.5 wt. percent of nickel ricinoleate) As in Example 4, two comparative runs were made to determine the effect of the use of the indicated catalyst. The charge and procedure in this example were the-same as in Example 1, except for the inclusion of 614g. of

. nickel ricinoleate (7.5 wt. percent, calculated on the basis of Ni, and based on the amount of barium and nickel ricinoleates charged), g. being added to the initial reactor charge, and the balance being well mixed with the barium ricinoleate (121 g. of this barium salt were used); the indicated catalyst addition was made in only one or the runs, the amount of barium ricinoleate used in the other run being 735 g. The sebacic acid yield in the catalyzed run represented an increase of 33.8% over the .sebacic acid yield in the corresponding runrnade with out catalyst.

Example 11. (Methyl ricinoleate; 7.5 wt.. percentof nickel chloride) As in Example 4, two comparative runs were made to determine the effect of the use of the indicated catalyst.

"The charge to the Inconel reactor was 720 g. of sodium hydroxide 512.8 g. of Ba(OH) -'5H O; in the catalyzed run, 5-1 59 g.- of nickel chloride'(7 .5 -wt. percent, calculated on the basis of Ni, and based on the amount of methyl ricinoleate charged) were also charged to the reactor initially. After the temperature of the pot contents had been raised to the reaction temperature of 285 -3 00 C., the addition of 312.5 g. of purified methyl ricinoleate via the separatory funnel (no powder funnel was used in this example) was started, and was completed in 1.0 hour. The procedure, in other respects than those indicated was the same as that used in Example 1. The sebacic acid yield in the catalyzed run represented an increase of 34.7% over the sebacic acid yield in the corresponding run made without catalyst.

Example 12. (Ricinoleyl alcohol; 7.5 wt. percent of nickel benzoate) As in Example 4, two comparative runs were made to determine the effect of the use of the indicated catalyst. The charge to the Inconel pot was 1010 g. of potassium hydroxide and 449 g. of Ba(OH) -5H O; in the catalyzed run, 54.9 g. of nickel benzoate (7.5 wt. percent, calculated on the basis of Ni, and based on the amount of ricinoleyl alcohol charged) were also charged to the reactor initially. After the pot contents had been heated to the reaction temperature of 360375 C., the addition of 142.5 g. of purified ricinoleyl alcohol via the separatory funnel was started, and was completed in 1.5 hours. The procedure, except as indicated, was patterned after that of Example 1. The sebacic acid yield in the catalyzed run represented an increase of 31.9% over the sebacic acid yield in the corresponding run made without catalyst.

Example 13. (Sodium ricinoleate; 20 wt. percent of nickel) As in Example 4, two comparative runs were made to determine the efiect of the use of the indicated amount of nickel catalyst. The charge to the Inconel pot was 400 g. of sodium hydroxide and 512.8 g. of

in the catalyzed run, 64.1 g. of Raney nickel catalyst (20 wt. percent of nickel, based on the amount of'sodium ricinoleate charged) were also charged to the reactor initially. After the pot contents had been heated to the reaction temperature of about 250 C., 320.5 g. of sodium ricinoleate (tech.) were added to the reactor through a powder funnel over a period of 1.25 hours. On completion of the addition of the ricinoleic compound, the heating was discontinued, and the product was worked up in the manner used in the preceding examples. The procedural steps, other than those indicated, were as per those used in Example 1. The sebacic acid yield in'the catalyzed run represented an increase of 33.9% over the sebacic acid yield in the corresponding run made without catalyst.

The reactions in the foregoing examples went smoothly and with no foaming. But, when the barium compound was omitted from runs otherwise paralleling these examples, the resulting foaming was such as to make the process unsatisfactory from a practical standpoint. The process of this invention can also be conducted in a continuous manner, with constant charging of reactants to the fusion bath and constant removal of reaction products therefrom, with recycling of alkali metal hydroxide and barium compounds to the reactor. The most noteworthy efiect of the inclusion of the catalysts of this invention is'the vastly improved yields of sebacic acid and capryl alcohol which are realized. Another desirable feature of this invention is that the improved yields enable the use of simplified recovery techniques for the sebacic acid, as the yields obtainable by the process of this invention are indicative of the fact that the corresponding products are not as contaminated with fatty materials (unconverted reactants) as is the case with prior art processes.

The instant reaction proceeds simply without the need of such prior art requirements as super-atmospheric pressures and the presence of inert organic liquids, and the process has the added advantage of eliminating the need for neutralization of the alkali fusion bath. The particular apparatus used in the foregoing examples is not essential to the process of this invention, as this process can be conducted in any equivalent'apparatus which is not subject to attack by hot alkalis and which is suitably equipped for agitation of the reaction mass, introduction of the reactants, and recovery of the reaction products.

What is claimed is:

1. A process for the conversion of ricinoleic compounds into a salt of sebacic acid, which comprises charging a ricinoleic compound and water to an enclosure containing a heated, fluid alkali metal hydroxide bath, said bath containing a barium compound in an amount of from about 0.5 to about 5.0 moles per mole-equivalent of ricinoleic compound and a catalyst selected from the group consisting of nickel, inorganic nickel compounds, and nickel salts of organic acids.

2. The process of claim 1, in which said ricinoleic compound is an alkali metal salt of ricinoleic acid.

3. The process of claim 1, in which said ricinoleic compound is a ricinoleic acid ester.

4. The process of claim 1, in which said ricinoleic compound is barium ricinoleate.

5. The process of claim 1, in which said ricinoleic compound is ricinoleyl alcohol.

6. The process of claim 1, in which said alkali metal hydroxide is sodium hydroxide.

7. The process of claim 1, in which said barium compound is barium hydroxide.

8. The process of claim 1, in which said barium compound is barium chloride.

9. The process of claim 1, in which the amount of said water charged to said enclosure is sufiicient to maintain from about 4 to about 5 moles of water per mole-equivalent of ricinoleic compound in the reaction zone.

10. The process of claim 1, in which said bath contains at least about 5 moles of alkali metal hydroxide per moleequivalent of ricinoleic compound.

11. The process of claim 1, in which said catalyst is present in an amount of from about 0.2 to about 20 wt. percent (calculated on the basis of Ni), based on the amount of said ricinoleic compound.

12. The process of claim 1, in which said catalyst is finely divided nickel.

13. The process of claim 1, in which said bath is heated to from about 225 to about 375 C.

14. The process of claim 1, in which said bath is heated to from about 225 to about 300 C.

References Cited in the file of this patent UNITED STATES PATENTS 2,217,516 Houpt Oct. 8, 1940 2,304,602 Schrauth et al Dec. 8, 1942 2,580,931 Lane Ian. 1, 1952 2,734,916 Bolley et a1. Feb. 14, 1956 FOREIGN PATENTS 652,355 Great Britain Apr. 25, 1951 

1. A PROCESS FOR THE CONVERSION OF RICINOLEIC COMPOUNDS INTO A SALT OF SEBASIC ACID, WHICH COMPRISES CHARGING A RICINOLEIC COMPOUND AND WATER TO AN ENCLOSURE CONTAINING A HEATED, FLUID ALKALI METAL HYDROXIDE BATH, SAID BATH CONTAINING A BARIUM COMPOUND IN AN AMOUNT OF FROM ABOUT 0.5 TO ABOUT 5.0 MOLES PER MOLE-EQUIVALENT OF RICINOLEIC COMPOUND AND A CATALYST SELECTED FROM THE GROUP CONSISTING OF NICKEL, INORGANIC NICKEL COMPOUNDS, AND NICKEL SALTS OF ORGANIC ACIDS. 